The Reed Neuromagnetism Laboratory with a single channel magnetometer has: (1) mapped the MEG and EEG of a human partial seizure, (2) mapped simultaneous MEG and subdural electrode of the human epileptic interictal spike, (3) used different EEG triggers to separate different spike populations in the epileptic focus, (4) modeled the MEG forward solution of a known current dipole in a human cadaver head, and (5) participated in an active collaboration with Dr. Terance M. Darcey who has modeled a moving dipole to fit both the MEG and EEG of a tangentially oriented human interictal spike mapped at UCLA. Further studies are being performed on those patients who have very frequent interictal spikes. This is anticipated to be productive but markedly limited in numbers studied and in the completeness of the information obtained. We proposed a systematic series of studies designed to extend epileptic source identification from the ideal computer model to realistic situations of interictal spikes and the seizure itself. The limitation of a single channel magnetometer prevents the natural extension of research into promising areas which have been developed at Reed and proved capable of study in the human partial seizure and in simultaneous MEG and subdural electrode monitoring. We have gone as far as we can go with 1 channel and cannot go further with our present system. A multichannel neuromagnetometer is essential to the proposed studies of the spatiotemporal structure of the MEG and EEG of the human partial seizure and of the simultaneous MEG, EEG and intracranial subdural EEG of the human interictal spike focus. In this renewal, we request the funds for a 7-channel neuromagnetometer and the salary for personnel, both essential to continue the proposed investigation of the MEG, comparison of the MEG and EEG, and integrated use of their complementary information to identify intracranial electric current sources. Funds are requested for essential consulting collaboration with Dr. Terrance Darcey at Yale University School of Medicine, New Haven, Connecticut, to model the MEG and EEG and to develop new modeling procedures to analyze the human epileptic focus. We have obtained half the funds for the neuromagnetometer from other sources and those have been completely exhausted. The funds requested here are the minimum essential to continue the research.